如果只是单一的TCP通信
如果你的silverlight应用因为一些特殊原因跟WCF通信时使用的不是Http协议，而是TCP协议，并且是Host到控制台上的。那么假设是下面这个简单的服务：
1，WCF中的主机服务代码如下：
class
Program
{
static void Main( string [] args)
{
ServiceHost host = new ServiceHost( typeof (HelloService));
host.Open();
Console.WriteLine( " 服t务?已?经-启?动ˉ！? " );
}
}
[ServiceContract]
interface IHelloService
{
[OperationContract]
string SayHello( string name);
}
public class HelloService : IHelloService
{
public string SayHello( string name)
{
return " hello, " + name;
}
}
{
static void Main( string [] args)
{
ServiceHost host = new ServiceHost( typeof (HelloService));
host.Open();
Console.WriteLine( " 服t务?已?经-启?动ˉ！? " );
}
}
[ServiceContract]
interface IHelloService
{
[OperationContract]
string SayHello( string name);
}
public class HelloService : IHelloService
{
public string SayHello( string name)
{
return " hello, " + name;
}
}
2，app.config可以简单配置成这样：
<
configuration
>
< bindings >
< netTcpBinding >
< binding name ="netTcpBindConfig" >
< security mode ="None" />
</ binding >
</ netTcpBinding >
</ bindings >
< services >
< service name ="HelloService" >
< host >
< baseAddresses >
< add baseAddress ="net.tcp://localhost:4503/HelloService" />
</ baseAddresses >
</ host >
< endpoint address ="" binding ="netTcpBinding" contract ="WCF.IHelloService" ></ endpoint >
< endpoint address ="mex" binding ="mexTcpBinding" contract ="IMetadataExchange" ></ endpoint >
</ service >
</ services >
< behaviors >
< serviceBehaviors >
< behavior name ="WCF.HelloServiceBehavior" >
< serviceMetadata />
< serviceDebug includeExceptionDetailInFaults ="false" />
</ behavior >
</ serviceBehaviors >
</ behaviors >
</ configuration >
< bindings >
< netTcpBinding >
< binding name ="netTcpBindConfig" >
< security mode ="None" />
</ binding >
</ netTcpBinding >
</ bindings >
< services >
< service name ="HelloService" >
< host >
< baseAddresses >
< add baseAddress ="net.tcp://localhost:4503/HelloService" />
</ baseAddresses >
</ host >
< endpoint address ="" binding ="netTcpBinding" contract ="WCF.IHelloService" ></ endpoint >
< endpoint address ="mex" binding ="mexTcpBinding" contract ="IMetadataExchange" ></ endpoint >
</ service >
</ services >
< behaviors >
< serviceBehaviors >
< behavior name ="WCF.HelloServiceBehavior" >
< serviceMetadata />
< serviceDebug includeExceptionDetailInFaults ="false" />
</ behavior >
</ serviceBehaviors >
</ behaviors >
</ configuration >
3，鉴于silverlight4在访问服务的时候会请求主机的80端口得到一个策略文件，如果你按照这个要求在wwwroot下放置这么个xml的策略文件：
<?
xml version="1.0" encoding="utf-8"
?>
< access-policy >
< cross-domain-access >
< policy >
< allow-from http-request-headers ="*" >
< domain uri ="*" />
</ allow-from >
< grant-to >
< socket-resource port ="4502-4534" protocol ="tcp" />
</ grant-to >
</ policy >
</ cross-domain-access >
</ access-policy >
< access-policy >
< cross-domain-access >
< policy >
< allow-from http-request-headers ="*" >
< domain uri ="*" />
</ allow-from >
< grant-to >
< socket-resource port ="4502-4534" protocol ="tcp" />
</ grant-to >
</ policy >
</ cross-domain-access >
</ access-policy >
那这个服务就OK了。可以正常提供服务了。
如果需要加载另外的DLL，且这DLL访问http的WCF服务呢？
也许您在VS2010中调试会OK，但是在部署到服务器上后，打开页面会发现一个错误，提示的居然是安全性错误。会是什么原因呢，我百思不得其解，奇怪的地方就在于，为什么在VS2010中调试加载的DLL可以正常访问服务，但是一发布就访问不到了呢。后来，在同事的提醒下，我在wwwroot下的文件clientaccesspolicy.xml中加了一行配置：
<
resource
path
="/"
include-subpaths
="true"
/>
全部配置为：
<?
xml version="1.0" encoding="utf-8"
?>
< access-policy >
< cross-domain-access >
< policy >
< allow-from http-request-headers ="*" >
< domain uri ="*" />
</ allow-from >
< grant-to >
< socket-resource port ="4502-4534" protocol ="tcp" />
< resource path ="/" include-subpaths ="true" />
</ grant-to >
</ policy >
</ cross-domain-access >
</ access-policy >
< access-policy >
< cross-domain-access >
< policy >
< allow-from http-request-headers ="*" >
< domain uri ="*" />
</ allow-from >
< grant-to >
< socket-resource port ="4502-4534" protocol ="tcp" />
< resource path ="/" include-subpaths ="true" />
</ grant-to >
</ policy >
</ cross-domain-access >
</ access-policy >
再打开页面，通过！
补充：由于silverlight在访问WCF服务时，需要在80端口获取一个策略文件，而这个策略文件便是给了silverlight一个访问主机的权限。由于我们的silverlight应用本身是访问TCP协议的WCF的，所以需要在wwwroot下放一个策略文件允许TCP的访问，但是由于silverlight应用中又加载了一个DLL，这个DLL是访问HTTP协议的WCF的，所以在请求TCP授权的同时，需要获得HTTP的授权，而<resource path="/" include-subpaths="true"/> 这个配置节正是满足了访问IIS根目录及子目录的权限，当然，包括WCF服务在内。
